Background of the Invention
[0001] The present invention generally relates to lancing devices for lancing dermal tissue
and for withdrawing a fluid sample.
[0002] Lancets in conventional use generally have a rigid body and a sterile needle which
protrudes from one end. The lancet may be used to pierce the skin, thereby enabling
the collection of a blood sample from the opening. The blood is then transferred to
a test collection device. Blood is most commonly taken from the fingertips, where
there is generally an abundant supply. However, the nerve density in this region causes
significant pain in many patients. Sampling of alternate sites, such as earlobes and
limbs, is sometimes practiced to access sites which are less sensitive. These sites
are also less likely to provide sufficient blood volume, and make blood transfer directly
to test devices difficult.
[0003] Repeated lancing in limited surface areas (such as fingertips) results in callous
formation. This leads to increased difficulty in drawing blood and increased pain
to the user. To reduce the anxiety of piercing the skin and the associated pain, many
spring loaded devices have been developed.
[0004] After puncturing the skin, conventional lancing devices are laid down and the free
hand of the user squeezes blood from the puncture wound. This technique requires a
clean storage site for the lancing device and a two-hand operation. Once the drop
of blood is expressed from the lancing site, the user transfers the blood to a test
strip of a suitable meter.
[0005] It is often desirable to collect the expressed sample from the patient and then introduce
the sample to a test device in a controlled fashion. Some blood glucose monitoring
systems, for example, require that the blood sample be applied to a test device which
is in contact with a test instrument. In such situations, bringing the finger of a
patient directly to the test device poses some risk of contamination from blood of
a previous patient. With such systems, particularly in hospital settings, it is common
to lance a patient, collect a sample in a micropipette via capillary action and then
deliver the sample from the pipette to the test device.
[0006] However, these lancet devices do not extract ('squeeze out') a sufficient sample
from the various surfaces for lancing. For example, the curved surface of a fingertip
requires the right amount of pressure to be applied to extract blood quickly and efficiently
from the patient. Therefore, there is a need for a lancet system that can accommodate
the lancing of curved surfaces (e.g., fingertips) as well as flat surfaces (e.g.,
forearm or leg) to express sufficient volume of blood or interstitial fluid, while
concomitantly reducing pain experienced by the user.
[0007] EP 0 783 868 A1 discloses an assembly for adjusting the piercing depth of a lancet. The assembly
comprises a cap mounted on an injector and having a stop means constructed so that
an end of the lancet housing abuts against the stop means after ejecting the lancet
so that movement of the lancet housing is stopped while the lancet is outside of the
cap, a cover element through which the lancet extends which has an opening against
which the user's skin is placed, and an adjusting element which engages the cap and
the cover element.
[0008] WO 97/43962 discloses a lancing device according to the preamble of claim 1.
Summary of the Invention
[0009] The present invention provides a lancing device as recited in the claims.
[0010] In accordance with one aspect of the present invention, the cap body is transparent
to facilitate viewing of the quantity of blood expressed.
[0011] In accordance with a further aspect of the present invention, the cap is removably
and replaceably connected to the distal end of the housing.
[0012] In accordance with another aspect of the present invention, the sleeve can be biased
toward the distal end of the cap body, for example, by a spring.
Brief Description of the Drawings
[0013] These and other features and advantages of the present invention will be more fully
understood by reference to the following detailed description in conjunction with
the attached drawings in which like reference numerals refer to like elements through
the different views. The drawings illustrate principles of the invention and, although
not to scale, show relative dimensions.
FIG. 1 is a side elevational view of a cap for a lancing device, illustrating the
cap attached to a lancing device not in accordance with the teachings of the present
invention;
FIG. 2 is a side elevational view of the cap of FIG. 1;
FIG. 3A is an end view of the cap of FIG. 1;
FIG. 3B is an end view of the cap of FIG. 1, wherein an anti-slip material is affixed
to the contact ring;
FIG. 4A is a side elevational view in cross section along line 4-4 of FIGure 3, illustrating
the contact ring of the cap of FIG. 3;
FIG. 4B is a graphic representation of the pressure profile created by the cap of
FIG. 2;
FIG. 4C is a cross-sectional view of an alternate embodiment of the contact ring of
the lancing device not according to the present invention;
FIG. 5 is a side elevational view of an embodiment of the cap for a lancing device
of the present invention, illustrating a sleeve positioned about the cap in accordance
with the teachings of the present invention
FIG. 6 is an end view of the cap of FIG. 5;
FIG. 7 is a side elevational view of the cap of FIG. 5, illustrating the cap displaced
from the skin in accordance with the teachings of the present invention;
FIG. 8 is a side elevational view of the cap of FIG. 5, illustrating the cap in contact
with the skin in accordance with the teachings of the present invention;
FIG. 9 is a front elevational view of the cap of FIG. 5;
FIG. 10 is a front elevational view of another embodiment of a cap for a lancing device,
suitable for lancing a fingertip not in accordance with the teachings of the present
invention;
FIG. 11 is an end view of the cap of FIG. 10;
FIG. 12 is a front elevational view of another embodiment of a cap for a lancing device
for lancing the ventral side of a fingertip not in accordance with the teachings of
the present invention;
FIG. 13 is an end view of the cap of FIG. 12;
FIG. 14 is a side view of an alternate embodiment of a cap not according to the present
invention formed of a flexible material and disposed in a rest position;
FIG. 15 is a side view of the cap of FIG. 14 when the contact ring contacts the lancing
site;
FIG. 16 is a side view of an alternate embodiment of a cap not according to the present
invention formed of a deformable, flexible material and disposed in a rest position;
and
FIG. 17 is a side view of the cap of FIG. 16 when the contact ring contacts the lancing
site.
Description of Illustrated Embodiments
[0014] The present invention is directed to a cap for use with a lancing device for lancing
dermal tissue to express a fluid sample, such as blood, interstitial fluid, or both.
We refer below to the expression of blood for purposes of simplicity, although it
is intended to encompass the expression of interstitial fluid or both. The cap of
the present invention is designed to facilitate the expression of blood after the
dermal tissue is lanced by increasing the pressure on the dermal tissue surrounding
the lancing site. This increase in pressure results in increased blood flow from the
lancing site, thereby reducing the time necessary to express a sufficient quantity
of blood and eliminating the need for placing the lancing device on a surface and
using the other free hand to squeeze out the sample fluid.
[0015] Moreover, the cap of the present invention is particularly suited for collecting
blood samples from lancing sites other than on the fingertip of the patient, which
is the traditional location for collecting blood samples. Use of such alternative
sites can be less painful to the patient and also allows the patient to "rest" his
or her fingertip. Suitable alternative sites include, but are not limited to, the
forearms, the upper arms, the thighs, the palms, and the abdomen of a patient. Blood
sample collection at alternative sites can be problematic as manually applying sufficient
pressure on the dermal tissue proximate the lancing site to collect the blood sample
can be difficult and typically results in low yields. The cap of the present invention
allows the user to increase the amount of pressure at the lancing site such that a
sufficient quantity of blood can be expressed from the alternative sample site.
[0016] A cap 10 not in accordance with the present invention is illustrated in FIGS. 1 through
4. The cap 10 is design to be connected to the distal end of the housing 12 of a conventional
lancing device. In a conventional lancing device a lancet 30 is mounted within the
housing 12 of the lancing device and is movable along a first axis, indicated by line
A in FIG. 1, relative to the housing 12. The lancet 30 can be driven along the first
axis by the lancing device to puncture the dermal tissue. The blood sample can then
be expressed for collection from the lancing site. Such conventional lancing devices
are available from Lifescan, Inc. of Milpitas, CA, Palco Laboratories of Santa Cruz,
CA, Therasense of Alameda, CA, and Amira Medical of Scotts Valley CA. In addition,
lancing devices are described in U.S. Patent Nos.
5,730,753 to Morita,
6,045,567 to Taylor, and
6,071,250 to Douglas. The cap of the present invention can be used with any lancing device employing a
movable lancet for lancing dermal tissue. Moreover, the present invention is intended
to include any device suitable for expressing a fluid sample from a user employing
different extraction techniques, including the use of lancets, hollow and solid needles
or microneedles, ultrasonic devices, thermal techniques, and the like. The device
can be a simple lancing device as described above, or can include devices having integrated
meters or measuring devices suitable for testing an analyte, such as glucose.
[0017] The cap 10 includes a cap body 14 having a proximal end 32 and a distal end 34 as
best illustrated in FIG. 2. A contact ring 16 is attached to the distal end 34 of
the cap body 36. An opening 18, shown in FIGS. 3A and 4, is provided in the contact
ring 16 to allow a portion of the lancet 30 to pass therethrough to effect puncturing
of the dermal tissue.
[0018] Referring to FIG. 2, the cap body 14 can include a connector 20 for removably and
replaceably connecting the proximal end 32 of the cap body 14 to the distal end of
the housing 12 of the lancing device. The connector 20 preferably is threaded to mate
with corresponding threads provided in the housing 12 of the lancing device. One skilled
in the art will recognize that alternative connecting mechanisms may be used. For
example, the connector 20 can be sized and shaped to snap-fit to the housing 12. In
addition, the cap 10 can be permanently affixed to the housing 12, although, it is
preferable for the cap 14 to be removably and replaceably connected to the housing
12.
[0019] The cap body 14 can be constructed from a transparent, translucent or opaque material,
such as a clear, transparent plastic, or includes a transparent portion forming a
window to the interior of the cap body, or can be constructed of conventional non-transparent
material. If transparent, the material should be sufficiently so to permit expressed
blood to be viewed within the cap body 14. The transparency of the cap body 14 allows
the user to view the amount of blood expressed for collection from the lancing site,
as discussed in more detail below.
[0020] Referring to FIGS. 3A and 4A, the contact ring 16 preferably has a multi-contoured
surface 22 for contacting the dermal tissue both during lancing and during blood sample
expression. The multi-contoured surface 22 is oriented generally about a second axis,
indicated by line B in FIG. 4A, distinct from the first axis A. In the embodiment
described herein the second axis B is perpendicular to the first axis A. One skilled
in the art will recognize that the second axis is not limited to this preferred orientation
and that any orientation distinct from the axis of motion of the lancet can be employed.
[0021] The multi-contoured surface 22 is designed to pressure the dermal tissue to maximize
blood flow rate from the periphery of the pressured area to the center of the lancing
site and to facilitate the expression of a blood sample for collection. The term multi-contoured
surface as used herein is intended to include two or more surfaces oriented at distinct
angles with respect to each other and with respect to a common axis. The multi-contoured
surface can extend inwardly from a vertical wall, or can extend inwardly from a flat
surface extending radially inwardly from the vertical wall. Those of ordinary skill
will recognize that the multi-contoured surface can include any selected number of
surfaces. The surface can be, according to one practice, non-planar. In one embodiment
described herein, the multi-contoured surface 22 is comprised of an outer radial portion
24 and an inner radial portion 26 proximate the opening 18. The outer radial portion
24 is preferably oriented at a first angle C relative to the second axis B. The inner
radial portion 26 is preferably oriented at a second angle D, distinct from the first
angle C, relative to the second axis B. The outer radial portion 24 and the inner
radial portion 26 can have any selected surface feature or shape, e.g., can be linear,
stepped, or curved. In the illustrated embodiment, the outer radial portion 24 is
generally linear from the perimeter 28 of the contact ring 16 to the intersection
with the inner radial portion 26. Alternatively, the outer radial portion 24 can be
convex or concave in curvature. Additionally, the inner radial portion 26 is generally
concave in curvature, but can also be linear or convex.
[0022] As shown in FIG. 4A, the angle C, corresponding to the slope of the outer radial
portion 24, is in the range between about 5° and about 15°. Additionally, the radial
extent of the outer radial portion 24, generally illustrated by line E in FIG. 3A,
is preferably between about 25% to about 75% of the total radius of the contact ring
16, as measured from the center point CP of the contact ring 16 to the perimeter 28
of the contact ring 16. In an embodiment, the radial extent E of the outer radial
portion 24 is about 50% of the total radius of the contact ring 16.
[0023] The contact ring 16 can be constructed from plastic or other materials suitable for
use in a medical instrument. The contact ring 16 can have a non-transparent color,
such as white, that is distinct and in contrast from the color of the dermal tissue.
A contrasting color allows the user to better visualize the quantity of expressed
blood.
[0024] The contact ring 16 can be a separate, discrete component affixed to the cap body
14, or can be integrally formed with the cap body 14.
[0025] With reference to FIG. 4B, the contact ring 16 of the cap 10 is sized and dimensioned
to be placed in intimate facing contact with the skin of the user. When placed thereagainst,
the contact ring creates a pressure gradient that extends from the radial outer surface
inwardly towards the opening 18. Specifically, when the skin is lanced by the lancet
30, the contact ring 16, which is disposed about the lancing site, creates a pressure
gradient that urges fluid to flow toward the opening 18, as indicated by arrows 19.
[0026] The pressure profile 31 created by the cap 10 has pressure peaks 33 that coincide
with the perimeter portion of the cap, or with the start of the multi-contoured surface
22. The pressure is a maximum at this portion since the cap contacts the skin of the
user to a greater degree. When the surfaces of the multi-contoured surface extend
inwardly towards the opening 18 and away from the skin, the overall pressure decreases.
This forms a pressure gradient that extends from the outermost portion of the cap
10 to the opening 18. The illustrated pressure gradient 31 has decreases in a somewhat
uniform manner across the surface 24, and in a more rapid manner across surface 26.
Those of ordinary skill will recognize that the pressure profile will change as a
function of the configuration of the contact ring.
[0027] According to an embodiment not according to the invention, illustrated in FIG. 3B,
the contact ring 16 can include an anti-slip feature adapted to prevent the contact
ring 16 and the cap 10 from moving relative to (or across) the surface of the skin
during expression of a blood sample. According to one embodiment, the anti-slip feature
comprises a suitable anti-slip material 23, such as rubber or silicone, that is attached,
coupled or affixed to a portion of the multi-contoured surface 22 of the contact ring.
The anti-slip material 23 ensures sufficient friction between the contact ring and
the skin to resist movement of the contact ring relative to the skin surface. According
to an alternate embodiment, the multi-contoured surface can be formed ro have selected
surface features, such as protrusions or indentations, or can be roughened, to increase
the friction between the contact ring and the skin. Alternatively, the entire contact
ring can be formed from an anti-slip material to prevent movement.
[0028] FIG. 4C illustrates another embodiment of the contact ring 16 of the cap 10 not according
to the present invention. Like reference numerals designate like or similar parts
plus a superscript prime. The illustrated contact ring 16' has an axially or vertically
extending outer wall or perimeter 28' that terminates at a distal end 29. The distal
end 29 includes a first flat face portion 29A that is adapted to press against the
skin of the user during use. The flat face portion 29A is generally perpendicular
to the perimeter portion 28'. The multi-contoured surface 22' extends radially inwardly
from the flat face portion 29A towards the opening 18'. The multi-contoured surface
22' extends between the annular flat face portion 29A, as indicated by the designation
L. The multi-contoured surface can also be configured to include the flat face portion
29A. In this embodiment, the multi-contoured surface includes three surfaces. Optionally,
an anti-slip feature, comprising an anti-slip material or a roughened surface, may
be incorporated in the contact ring 16' to prevent movement of the contact ring relative
to the skin surface during expression of the blood sample.
[0029] The illustrated multi-contoured surface 22' includes two or more surfaces oriented
relative to each other to form different, distinct angles. In particular, the multi-contoured
surface 22' includes a pair of surfaces 25 and 27. The radially outer surface 25 is
oriented at a first angle relative to the axis B. The radially inner surface 27 is
oriented at a second angle relative to the axis B different from the first angle.
As described above, the surfaces 25 and 27 can have any selected shape or angle.
[0030] In use, the cap 10 is connected to the housing 12 of the lancing device and the dermal
tissue is lanced by the lancet 30 passing through the opening 18 in the contact ring
16. The lancet 30 is then withdrawn into the cap 10 or the lancing device. The contact
ring 16 is pressed into contact with the dermal tissue proximate the lancing site
causing blood to exit the lancing site and enter the cap 10 through the opening 18.
Dermal tissue is "squeezed" into contact with the outer radial portion 24 and the
inner radial portion 26 of the multi-contoured surface 22. The multi-contoured surface
22 facilitates blood expression by increasing the hydrostatic pressure on the dermal
tissue in contact with the perimeter 28 of the contact ring 16. The hydrostatic pressure
on the dermal tissue decreases as the slope of the outer radial surface 24 and the
inner radial surface changes toward the opening 18. This inwardly extending pressure
gradient is illustrated in FIG. 4B. Experimental testing has revealed that 1.5 ml
to 3 ml of blood can easily be expressed from the lancing site using the cap 10 of
the present invention at sampling sites other than the finger. In addition, because
the cap body 14 can be transparent and the contact ring can be a contrasting color,
such as white, the user can easily monitor the volume of blood expressed.
[0031] An embodiment of the cap of the present invention is illustrated in FIGS. 5 through
9, in which a sleeve 60 is mounted about the cap body 14. The sleeve 60 is movable
generally along the first axis A, i.e., along the axis of motion of the lancet, and
relative to the cap body 60. The sleeve 60 comprises an annular collar 62 and at least
two legs 64A and 64B that extend from the collar 62 in the direction of the first
axis A toward the distal end 34 of the cap 10. The legs 64A and 64B taper from an
increased width proximate the collar 62 to a decreased width proximate the contact
ring 16.
[0032] As illustrated in FIG. 6, the legs 64A and 64B are arcuate in cross-section and encompass
only a portion of the circumference of the contact ring 16. The legs 64A and 64B are
preferably symmetrically disposed about the circumference of the contact ring 16.
Although only two legs are illustrated, one skilled in the art will appreciate that
additional legs can be added without departing from the present invention. In addition,
the legs need not be positioned symmetrically about the contact ring 16.
[0033] The sleeve 60 is preferably slidable along an axis parallel to the first axis A,
as indicated by arrow T in FIG. 5. A longitudinally extending slot 66 can be formed
in one or both of sides of the cap body 14. A protruding guide member 68 can be formed
in one or both of the legs 64A and 64B. The guide member 68 is sized and shaped to
slide within the slot 66 and inhibits lateral motion of the sleeve 60 relative to
the cap body 14. Alternatively, the slot 66 can be formed in one or more of the legs
64A and 64B and the guide member 68 can be formed on the cap body 14.
[0034] A spring 70 or other biasing mechanism can be provided to bias the sleeve 60 toward
the distal end of the cap 10. One skilled in the art will appreciate that the sleeve
60 is not limited to use with the cap 10 of the present invention, but can be used
with the cap of any lancing device.
[0035] It is sometimes desirable to remove the cap 10 and the contact ring 16 from contact
with the dermal tissue after lancing, for example, to remove pressure from the dermal
tissue or to visibly inspect the lancing site. The sleeve 60 allows the user to maintain
a portion of the lancing device, the legs 64A and 64B of the sleeve 60, in contact
with skin when the cap 14 and the contact ring 16 are removed from contact with skin,
as illustrated in FIG. 7. Importantly, the legs 64A and 64B allow the user to maintain
the opening 18 in alignment with the lancing site when the contact ring is returned
into contact with dermal tissue, as illustrated in FIG. 8. According to one embodiment,
the sleeve legs 64A and 64B further include an anti-slip feature to prevent movement
of the sleeve relative to the skin. An anti-slip material, such as rubber or silicone,
may be affixed to the contact surface of the sleeve legs to prevent movement. Alternatively,
the anti-slip feature comprises a roughened surface where the sleeve legs contact
the skin.
[0036] Referring to FIG. 9, the legs 64A and 64B can be spaced apart a distance sufficient
to allow a finger 80 of the user to fit between the legs 64A and 64B. The surfaces
67 connecting the two legs 64A and 64B can be curved, and are preferably parabolic
in shape, to further facilitate the user's finger 80. In addition, the legs 64A and
64B, as well as the sleeve 60, can be constructed from a flexible, resilient material,
such as a flexible plastic. The preferred material of choice is ABS plastic. As illustrated
in FIGure 9, the user's finger 80 can be positioned between the legs 64A and 64B when
the sleeve 60 is positioned beneath the cap 10. The legs 64A and 64B compress the
user's finger therebetween to pinch or squeeze the dermal tissue. The user's finger
can then be lanced and the compression of the user's finger by the legs 64A and 64B
can facilitate the expression of blood from the lancing site.
[0037] Alternate embodiments of a cap not according to the present invention are illustrated
in FIGS. 10 through 13, in which the contact ring 16 is designed for lancing the sharp
curve (or side) of the fingertip, as well as the ventral side of the fingertips.
[0038] FIGS. 10 and 11 illustrate another embodiment of a cap not according to the present
invention. The cap 80 includes a cap body 81 having a proximal end 86. A contact ring
85 is attached to the distal end 83 of the cap body 81. An opening 92 is provided
in the contact ring 85 to allow a portion of the lancet 30 to pass through to effect
puncturing of the fingertip. The illustrated cap body 81 can include a connector 84
for removably and replaceably connecting the proximal end 86 of the cap body 81 to
the distal end of the housing 12 of the lancing device. For example, the connector
84 can be sized and shaped to fit the housing 12. The cap 80 can be permanently affixed
to the housing 12, although it is preferable that the cap 80 be removably and replaceably
connected to the housing 12.
[0039] The cap body 81 is constructed from transparent, translucent, or opaque material,
such as clear or transparent plastic, or includes a transparent portion forming a
window to the interior of the cap body. The material should be sufficiently transparent
to allow the blood being expressed from within the cap body 81 to be viewed by the
user. The transparency of the cap body 81 allows the view the amount of blood expressed
for collection from the lancing, etc.
[0040] The contact ring 85 preferably employs a pair of pressure wings 82 sized and dimensioned
to accommodate the sharp curve of the fingertip therebetween. The pressure wings 82
thus form a recess 87 for accommodating the finger of the user. This applies the correct
amount of pressure to allow for the expression of blood.
[0041] Referring to FIG. 11, the pressure wings extend radially outward and away from the
contact ring for contacting the fingertip both during lancing and during blood sample
by pressing. The pressure wings 82 and 82 constitute a multi-contoured surface that
extends from the outer periphery of the body 81 to the opening 92. The multi-contoured
surface 88 is designed to pressure the fingertip to maximize blood flow rate from
the lancing site and to facilitate the expression of blood for sample collection.
The illustrated multi-contoured surface 88 comprises two or more non-planar surfaces
disposed at distinct angles relative to each other and with respect to a common axis.
For example, the pressure wings 82, 82 that constitute the multi-contoured surface
88 is comprised of a radial outer portion 88A and a curved radial inner portion 88B
proximate to the opening 92. The transition point between the surfaces 88A and 88B
can be arcuate, rounded, or sharp.
[0042] The illustrated contact ring 85 can be constructed from plastic or other materials
suitable for use in a medical instrument. The contact ring 85 can have a non-transparent
color that is distinct from the color of the fingertip. White is the preferred color
of choice. A contrasting color allows the user to better visualize the quantity of
blood expressed. The contact ring 85 can be a separate, discrete component affixed
to the cap body 81, or can be integrally formed with the cap body 81.
[0043] When in use, the cap 80 is connected to the housing 12 of the lancing device, and
the fingertip of the user is placed in the recess 87 formed by the pressure wings
82, 82. The lancet 30 of the device is deployed and passes through the opening 92
in the contact ring 85 to pierce the skin. The contact ring 85 is pressed into contact
with the fingertip proximate to the lancing site to express blood. The multi-contoured
surface 87 facilitates blood expression by creating a pressure gradient that extends
radially inwardly towards the opening 92. According to an alternate embodiment, an
anti-slip feature on the contact ring 85 prevents movement of the contact ring relative
to the skin surface when the contact ring is pressed into contact with the fingertip.
As discussed, the anti-slip feature can comprise a suitable anti-slip material affixed
to the multi-contoured surface, or a roughened multi-contoured surface. Alternatively,
the contact ring 85 can be constructed entirely of a suitable anti-slip material to
provide an anti-slip feature.
[0044] FIGS. 12 and 13 illustrate another embodiment of the cap not according to the present
invention. As illustrated in FIG. 12, the cap 90 includes a contact ring 95 attached
to the distal end 97 of the cap body 94. An opening 124 formed in the contact ring
95 allows a portion of the lancet 30 to pass therethrough to create a puncture on
the ventral side of the fingertip.
[0045] The cap body 94 includes a connector 99 for removably and replaceably connecting
a proximal end 98 of the cap body 94 to a distal end of the housing 12. For example,
the connector 99 can be sized and shaped to fit the housing 12. Also, the cap 90 can
be permanently affixed to the housing 12. Preferably, the cap 93 is removably and
replaceably connected to the housing 12. The cap body 94 is preferably similar to
cap body 81 of FIG. 10. The materials of cap 80 are also the same for cap 93. The
material can be transparent or include a transparent portion to allow expressed blood
to be viewed within the cap 93.
[0046] The illustrated contact ring 95 has a multi-contoured surface 96 that extends from
the periphery of the cap body 94 to the central opening 101. The multi-contoured surface
96 can include two or more surfaces disposed at distinct angles relative to each other
and with respect to a common axis. For example, the illustrated multi-contoured surface
96 is comprised of an outer radial portion 96A, a middle portion 96B, and an inner
radial portion 96C disposed proximate to the opening 101. The outer, middle and inner
radial portions of the cap can have any selected surface feature or shape, e.g., can
be linear, stepped, or curved. Moreover, the transition points between each surface
96A, 96B and 96C of the multi-contoured surface can have rounded, arcuate, or sharp
surface features.
[0047] The illustrated contact ring 95 can be constructed from plastic or other materials
suitable for use in a medical instrument. The contact ring 95 can have a non-transparent
color that is distinct from the color of the fingertip. White is the preferred color
of choice. A contrasting color allows the user to better visualize the quantity of
blood expressed. Similarly to cap 80, the contact ring 95 can be separated, discrete
component affixed to the cap body 94, or can be integrally formed with the cap body
94.
[0048] When in use, the cap 90 is connected to the housing 12 of the lancing device and
the fingertip is placed in intimate facing contact with the ventral side finger and
lanced by the lancet 30 passing through the opening 101 in the contact ring 96. The
lancet 30 is withdrawn into the cap 90 or lancing device. The fingertip is squeezed
into contact with the outer radial portion 96A, middle radial portion 96B, and inner
radial portion 96C of the multi-contoured surface 96. The multi-contour surface 96
facilitates blood expression by creating a pressure gradient that extends radially
inwardly toward the opening 101 from the perimeter 100 of the contact ring 95 or cap
body 94. According to one embodiment, an anti-slip feature on the contact ring 95
prevents movement of the contact ring relative to the skin surface when the contact
ring is pressed into contact with the fingertip. As discussed, the anti-slip feature
can comprise a suitable anti-slip material, such as rubber or silicone, affixed to
the multi-contoured surface. Alternatively, at least a portion of the multi-contoured
surface comprises a roughened contact surface to ensure friction between the contact
ring and the skin.
[0049] An alternative embodiment of the cap not according to the present invention is illustrated
in FIGS. 14-17 in which the contact region is designed with a flexible material for
lancing various surfaces of a user.
[0050] FIGS. 14 and 15 illustrate another embodiment of the cap for use at multiple different
lancing sites not according to the present invention. The illustrated cap 110 includes
a cap body 112 that terminates at a contact ring 114 mounted at a distal end. The
distal end 115 of the cap 110 can couple to the housing 12 via any suitable structure.
According to a preferred embodiment, the cap is permanently affixed to the housing,
and hence not axially movable relative thereto. The contact ring 114 of the cap 110
can include, if desired, a multi-contoured surface 118 having a plurality of surfaces
oriented at angles relative to each other. A central opening can also be formed therein.
According to an alternate embodiment, the contact ring can be a unitary structure
with nominal surface features formed therein.
[0051] The illustrated contact ring is preferably formed of a deformable, resilient, flexible
material that is capable of conforming to the shape of the body region of the user
placed in contact therewith. The contact ring can be preferably formed of a rubber
material, polyurethane, latex, or other flexible material. The cap body 112 can also
be formed of any suitable transparent, translucent, or opaque material, such as clear
or transparent plastic, or can include a transparent portion forming a window to the
interior of the cap body to enable the user to view the expressed blood. Alternatively,
the cap can be formed of a non-transparent material.
[0052] The contact ring 114 can be disposed in a rest position, FIG. 14, when not in contact
with a lancing site, and hence no shape is imparted to the ring. When placed in contact
with the lancing site, such as the ventral side of a finger, or any other suitable
portion of the finger, the contact ring conforms to the shape of the lancing site,
FIG. 15. According to one embodiment, an anti-slip feature on the contact ring 114
prevents movement of the contact ring relative to the skin surface when the contact
ring is pressed into contact with the fingertip. As discussed, the anti-slip feature
can comprise a suitable anti-slip material, such as rubber or silicone, affixed to
the multi-contoured surface. Alternatively, at least a portion of the multi-contoured
surface comprises a roughened contact surface to ensure friction between the contact
ring and the skin.
[0053] According to an alternate embodiment, as illustrated in FIGS. 16 and 17, a cap 130
includes a cap body 132 that has mounted thereto a deformable contact ring 134. The
illustrated contact ring 134 has edge portions 136 that extend over or outwardly from
the perimeter of the cap body 132. The contact ring can include, if desired, a multi-contoured
surface having a plurality of surfaces oriented at angles relative to each other.
A central opening can also be formed therein. According to an alternate embodiment,
the contact ring can be a unitary structure with nominal surface features formed therein.
[0054] The contact ring can be preferably formed of rubber material, polyurethane, latex,
or other flexible material. The contact ring 134 can be disposed in a rest position,
FIG. 16, when not disposed in contact with a lancing site, and hence no shape is imparted
to the ring. When placed in contact with the lancing site, such as the ventral side
of a finger, or any other suitable portion of the finger, the contact ring 134 conforms
to the shape of the lancing site, FIG. 17. Moreover, when disposed in this position,
the overhanging portions of the deformable contact ring, can 'flip' over and extend
along the outer surface of the cap body 132 so it can be used on a flatter skin area,
such as the forearm.
[0055] The cap body 132 can includes a connector for removably and replaceably connecting
a proximal end of the cap body 132 to a distal end of the housing 12. According to
one practice, the cap 130 can be permanently affixed to the housing 12. Preferably,
the cap 130 is removably and replaceably connected to the housing 12.
[0056] Since certain changes may be made in the above constructions without departing from
the scope of the invention, it is intended that all matter contained in the above
description or shown in the accompanying drawings be interpreted as illustrative and
not in a limiting sense.